Stewart grate construction for sintering-machines



A. L. LARSON. STEWART GRATE CONSTRUCHON FOR SINTERING MACHINES- PatentedApr. 5, 1921.

APPLICATION FILED AUGJOI I920. 1,373,620.

3 SHEETS-SHEET 1.

TORNEYS A. L. LARSON. STEWART GRATE CONSTRUCTION FOR SINTERING M ACH I NE S.

Patented Apr. 5, 1921.

APPLICATION FILED 16.20, 1920. 1,373,620.

3 SHEETS-SHEET Z.

' INVENTOR 1217.2 mar;

av T 72 if Q 771)! n ATTORNEYS A. L mason. STEWART GRATE CONSTRUCTIONFOR SINTERING MACHINES.

APPLICATION FILED AIM-1.20. I920- Apr. 5, 3 SHEETSSHEET 3- INVENTORAllamon f "L I f" RNEYS PATENT OFFICE.

auonsr L. reason, or xnnnoee, name.

STEWART GRA'I'E'CONSTR'UGTION FOB SINTEBING-MAOHINES.

Specification of Letters Patent.

Patented Apr: 5,12%}.

7 Application filed. August 20,1920. Serial No. 404,778

To all whom it may concern:

Be it known that I, AUeUs'r L. Laasorna citizen of the Dominion ofCanada, residing at Kellog in the county of Shoshone and State of daho,have invented certain new and useful Improvements in Stewart GrateConstructions for Sintering-Ma chines, of which the following is aspecification.

This invention has reference to improvements relating to what is knownas Dwight & Lloyd sintering machines and more particularly has referenceto improvements to that form of grate mechanism embodied in the presentpractical application of sinterin machines of the type mentioned, knownas the Stewart grate constructiom and invention is specificall directedto the improved arrangement 0 the grate bottomsof the pallets orcarriers embodied in such grate construction.

It is well known to those familiar with the use of sintering machines,that the modern type of such machines include a lar e numher, as high asforty-two individua pallets or carriers that travel along endless wa swith the ore contained therein which are su jected, during a art oftheir travel, to the desulfurizing an sintering operation, after which,in the return movement and inverted position, the loads of treated orecontained in the said individual pallet are discharged, the emptypallets traveling back to be again conveyed to their uppermost positionto be again recharged.

In the construction of sintering machines of the general type stated,each pallet has a grated bottom whose members are bolt'ed tightly to thepallet sides and as a result of such attachment, when the tes becomeheated and expansion takes p ace, the grate bars or members do not stayin the desired alinement and also, due to the heat of the furnace,clinkers frequently are formed in the slots of the grate surface,thereby greatly interfering with the extraction of the sulfuric gases.

To overcome this serious objectionable condition, it has been necessaryto station a man at each machine whose duty it was to clean the gratesas the pallets move around the furnace. L

the shovelingl .,cally made, easily applied for use, and

eral of the pallets or carriers 7 in o erative position.

Whic That this defect in the operation of the Dwight'& Lloyd smteringmachine be fully appreciated, it should be stated, by the improperexpansion grate lI'OIlS (and by the impro er expansion is meant that theheat of the urnace causes the ate members to expand in differentdirections) which results 1n the grate slots becoming tight on the oneside and leaving too much space at the other side, and since the ore int e traveling pallet is usually crushed fine, it (the ore) naturallypasses through such widened grate slots, often necessitating of tons ofthe wasted ore back into t through the roasting process.

Primarily, my invention has for its obiect to provide a grateconstruction for pa ets of sintering machines, which is selfcleaning andwhich practically overcomes the improper expansion of the rate irons andthe consequent elimination o the aforesaid ore wastage and extra laborrequired for gathering such wastage for retreatment.

Another and essential feature of my indesired or perfect of the r e binsto be again carried vention is the provision of a grate construction forsintermg machine pallets or ore carriers, in which the grate members areparticularly designed for being economiemplayed to a eater advantage ina number of respects t an can be present in the construction of gratebottoms of the character referred to and used in ore treating apparatus.

The preferred embodiment of my invention is illustrated in theaccompanying drawings in which sintermg machine are represented as issuflicient portions of a.

necessary to illustrate a practical application of my invention and inwhich:

Figure 1 is a side elevation of a portion of a sintering or ore roastingmachine sevbeing s own F1 2 is a diagrammatic sectional view illustratesa numb allets positioned as passing across the ore x of the sintering'machine J 'Fig. 3 is a detail cross section taken on the line 3-3 onFig. 2.

Fig. 4 is a plan view of a pallet equipped er of ore loade stationarygrate with my improved construction of grate bottom.

Fig. 5 is a cross section thereoffthe grate bars or irons being at thenormal or load carrying position.

Fig. 6 is a view similar to Flg. 5, the pallet being shown at a reversedor dumping position and the movable grate Irons at their shiftedposition for efi'ectmg the selfcleanin of the iron.

Fig. is a perspective view of one of the end grate bars.

Fig. 8 is a similar view of one of the mov able grate bars.

Fig. 9 is a perspective view of one of the ars.

Fig. 10 is a detail view illustrating the cooperative relation of theclamping bar shown in face View and the assembled rate units, the latterbeing shown in end e evation.

Figs. 11, 12 and 13 are detail cross sections taken on the lines 1111,12-l2 and 1313 on Figs. 7, 8 and 9, respectively.

As before stated, my improved grate construction is especially designedfor constituting the bottom of pallets or carriers that form anessential feature of the Dwi ht & Lloyd types of sintering machines anthat the o erative arrangement of such allets and their grateconstruction be readi y understood, a sintering machine of the kindstated is diagrammatically illustrated in Fig. 1 of the drawings and thecooperative arrangement of the members of the pallets or carriers withthe ways on which they travel and the air or suction box over which theypass is illustrated in Figs. 2 and 3 and, in the said Figs. 1, 2 and 3,1 designates the endless track that is arran ed to support and directthe series of pal ets or carriers 3, which serve as the supporters forthe ore durin the roasting and sintering bperation.

It s ould be stated, the allets in ractice, are caused to move slow y inthe irection indicated b the arrow the means for effpcting suc direction0? movement of the pallets for feeding the ore and for igniting the ore,after being delivered to the pallets, bein readily understood by thosefamilar wit the use of sintering machines of the type mentioned byreferring to Fig. 1' it being alsohinderstood that, after the ore hasbeen ignited, it passes with the pallets across the air box 2 and afterpassing from the air box, the said pallets, in their travel, passdownward over a circular path, overturning at-such point to discharwhatever load they may .carry, one of t e pallets bein the dischargepoint in ig. 1 an another indicated as returning down the inclined waytoward the other end for being again carried up in position forreloading in the same within the pallet to the said pallets shownpositioned at The general arrangement of a number of pallets orcarriers, their ates and the manner of sustainin such pi lets on theirides and ways is c early indicated in Figs. 2 and 3, which also show thenormal relation of the grate members and the means for confinin them inproper operative position frame. a

In the present construction of sintering machines of the type referredto, the grate bars are all fixedly held in place, either by bolting thegrate irons individuall to the sides of the pallets or by connectingbars made in an angled shape and whichv project slightly over the grate,such arrangement causing a percentage of the ore to pass through withouthaving the gases properly extracted, the said connecting barsusuallyrequiring six bolts for securing them in place, thereby causing someinconvenience, when it is necessary to remove or replace a gate iron.

eferring now more specifically to the essential features of myinvention, reference is made to Figs. 4, 5 and 6 of the drawings, whichillustrate a complete pallet in which is included my improvedconstruction of rate bars.

he grate bottom as shown, comprises two fixedly held end grate bars 44,two intermediate fixed ate members 5-5, three movable grate firs 6-6-6and two connecting bars 7-7, one of which is located at each end of thepallet or-box.

One of the movable grate members 6 mentioned is located between the pairof fixed grate members or bars 5-5 and .the other two movable members6-6 are located between a fixed bar and an end bar at their reectivesides of the pallet frame, as is best s own in Figs. 2, 4, 5 and 6.

The end bars 4, as also the intermediate or fixed grate members 6, areof like con- 'struction, one of each of the said end bars the movablebars and the intermediate fixe bars being shown in detail in Figs. 7, 8and 9, respectively.

It will be noticed by referring to Fig. 5, the adjacent edges 40, 50 and60 of the several end, the movable and the fixed grate bars are. taperedto allow for a certain amount of play of the movable bars sufiicientwhen the 6, for dum ing the ore, that the -'ars cause the movab e barsto shake in suc manner and to leave their normal position, shown inFigs. 2 and 5, and assume the position shown in Fig. 6 that the slots ors aces between the several ate bars are sel -cleaned and, as the movab 0bars 5, in practice, fall the distance of about one-half an inch,provides for forcin any ore on the grates, in the form of clin ers, outof the grate slots, the Ore falling into the proper bin.

pallet reaches the turning over or discharging position, shown in Fig;

y no

- other parts thereof, by

In my construction of grate the several bars 4, 5 and 6 have their en s'eculiarly shaped for cooperating with the coacting edges of theconnecting bars that hold the several bars 4, 5 and 6 downonto theinturned angled flanges 30 of the allet frame and, in my grateconstruction, t ere are two of such connecting bars:7, one for each endof the-pallet box or frame and for enga ing with their respective endsof the grate 7 ar.

Each connecting bar 7, one of which is shown in detail in Fig. 10 is ofsufficient length to extend across the ull width of the pal et box (seeFi A) and it'has three bolt holes -70-70 or receiving bolts 8 and eachbolt hole is elongated vertically for adjusting the bar 7 -to allow fora proper fitting of the connecting bar in connection with the severalfixed grate bars.

The lower edge of each connecting bar 7 is shaped for e ecting a simpleand easily fitted adjustment with the peculiarly shaped ends of theseveral ate bars 4, 5 and 6 and for such purpose, t c said lower edgehas a pair of pendent tapered lugs" 71-71 adapted for seating within taered sockets 51-51 in the adjacent ends 0 the grate bar 5, to therebyfixedly hold the said bar 6 down upon the allet flan s 30-30.

At the opposite -si es of the tapering lugs 71-71, the lower edge of thebar 7 has tapered sockets 72, three of such sockets being provided andmade of sufiicient width to allow the bearing faces of the movable gratebars 6' to move therebetween, when the pallet assumes the turned overgpsition, as indicated in Fig. 6, the slots eing tapered in such amanner to allow plenty of lay for the movable grates.

To provide a close fitting of the connecting bar 7 and also for holdingthe end grate bars as an integral art 0 the complete ate structure, so tat, under expansion and contraction, all of the grate members move tother, the opposite ends of the con necting reason f the In -likeextensions 7 3-7 3 that fit down into o -sets 40-40 in the ends of thebars 4-4, which ends are also beveled, on their top surface, as at 41,forthe close fitting of the tapering edges of the end sockets into whichthe outermost ones of the movable bars enter, as the drop from betweentheir adjacent end an fixed grate members.

One .of the "essential features 1n my grate construction, is the meansfor holding the specified grate bars from expanding irregularly and forsuch purpose, each of the fixed and the end grate bars, which relativelyfixed bars, at the opposite sides of their ends have vertical ribs 9that taper from the wi est or head ortion at the top face of the grate,to a ,-sha e endin at he bottom of, the bar and t 0 said 11 s 9 thefastening other side.

ar are of greater depth than the fixedly latter are also on the saidbars 4 and 5' are adapted for extending into like shaped verticalgrooves 10-10 on the adjacent edges of the movable bars 6, the taperedform of the ribs 9 and the ooves 10 permitting of free movement of t ebars 5 with respect to the other bar and reduces frictional binding ofsuch parts.

By providing positive contacting points between all 'of the grate barsthat constitute the complete set of grate bars and arranged in themanner described and shown w an the grate irons begin to expand, un erthe heat of the furnace, causes the entire pallet (all of the partsthereof being relatively in contact) to expand the same way and therebyreduces to the minimum danger of the grate irons expanding in differentdirections, the closing of the slots at one side and excessive wideningof other slots at the The means for holding the several grate bars inproper operative position on the pallet flanges 30 (the connectin bar 7)is such that the removal of the said ars is renders simgle and may bequickly effected and also ran ers it very convenient for removing and relacing a grate bar, when necessary.

rom the foregoing description taken in connection with the accompanyingdrawings, the complete construction, the manner of use and theadvantages of my invention, it is believed, will be readily apparent tothose skilled in the art to which my said invention relates.

What I claim is:

1. In a grate for ore carriers or pallets, a series of relativelyfixedly held grate irons and other grate irons coiiperative with theheld irons and movably mounted to the said fixedly held irons a limitedoutward drop relafixedly held arms, as the pallet tively to the orcarrier is inverted.

a pallet frame 2. In combination with having an inwardly extendedbearing flange along each of its ends; of a grate construction thatcomprises, a number ofrelatively held bars and a movable bar locatedbetween each pair of adjacent fixedly held bars and means along the endsof the pallets for limitin the outward movement of the said movab egrate bars as the pallet assumes a turned over position. 1

3. In an ore carrying pallet for sintering machines, the combinationwith a bearing flange along each of the opposite ends of the palletframe; of a series of alternately disosed relatively fixedly held gratebars havmg their opposite ends shaped torest upon 7 the aforesaidflanges, other grate bars inter- 12B mediate the relatively fixedly heldbars havin their ends shaped to rest upon the said en flanges of theallet frame and having movement outwar l with. respect to the saidrelatively fixed y held grate bars, and 180 III A bottom 'medlate gratebars and the ad means attachable to each of the pallet ends adapted forengagement with the endsof the several relatively fixedly held bars andprovided with stop portions for limiting the outward thrust of themovable bars, as the pallets assume a turned. over position.

4. In a sintering machine pallet, a grate that constitutes the bottom ofthe pallet, the said grate being composed of pairs of relatively fixedlyheld grate bars and other bars, one of said other bars intermediate eachpair of the relatively fixedly held bars, the said other bars havingmovement vertically between the said fixedly held bars, as the palletassumes the turned over position, and means on each of the opposite endsof the pallet for limiting the outward drop of the said movable bar andfor holding the other bars to their relatively fixed position.

5. In a sintering machine pallet, a grate including a series ofrelatively fixedly held bars and a series of other bars intermediate therelatively fixedly held bars, the said intermediate bars having verticalmovement between the other bars, as the pallet turns over, the saidmovable and fixedly held bars havin relatively slidable contactingportions at tfie opposite edges at each of their opposite ends for thepurpose stated.

6. In a ate construction for sintering machine pa lets, the combinationwith the pallet frame having an inturned bearing flange along theopposite sides and ends, a air of end grate bars that engage the sidgand end portions of the pallet flange, a plurality of intermediate gratebars whose opposite ends terminate in narrow extensions for resting uponthe opposite flanges at the opposite ends of the pallet, other gratebars between each pair of the intermediate grate bars and between theinterjacent end bars, the said intermediate bars having reduced endextensions for restin on the end flanges of the pallet frame, anconnecting bars removabl attachable one to each pallet end, the saidbars having their lower edge shaped for positively engaging the endextensions of the end and t e intermediate bars, whereby to fixedly holdthe said bars onto the pallet flange bearin portions that t and providedwith socket of the aforesaid over the end extensions other bars betweenthe fixedly held her, whereby to rovide for alimited outward movement 0?the said other bars between their adjacent bars for dislodging clinkersand the like, as the pallets assume their turned over position.

7 A grate construction for sintering machine pallets, comprising two endbars, two fixed bars, a movable bar between each end and an adjacentfixed bar, another movable bar between the fixed bars and means forchine pallets,

securing the several bars in their fixed and movable relation within thepallet frame, the said means comprising an internal bearing flange alongeach of the opposite ends of the allet frame, and a connecting barremova 1y attachable to each end of the pallet frame with the lower edgesitively enga d with the end and the dyed bars and aving socket ortionsthat fit over {)he adjacent ends of each of the movable ars.

8. A grate construction for sintering ma: chine pallets, comprising twoend bars, two fixed bars, a movable bar between each end and an adjacentfixed bar, another movable bar between the fixed bars and means forsecuring the several bars in their fixed and movable relation within thepallet frame, the said means comprising an internal hearing flange alongeach of the opposite ends of the allet frame and a connectin bar removaly attachable to each end 0% the pallet frame with the lower edgepositively engaged with the end and the fixed bars and having socketportions that fit over the adjacent ends of each of the movable bars,and means tending to constantly hold all of the grate bars in edgewise,contact with each other and with the pallet frame to thereby cause theentire pallet to expand together.

9. A grate construction for sintering macomprising two end bars, twofixed bars, a movable bar between each end and an adjacent fixed bar,another movable bar between the fixed bars and means for securing theseveral bars in their fixed and movable relation within the allet frame,the said means comprising an internal bearing flange along each of theopposite ends of the allet frame and a connectin bar removalilyattachable to each end 0 the pallet frame with the lower edge ositivelyengaged with the end and the fixed bars and having socket portions thatfit over the adjacent ends of each of the movable ha and means tendingto constantly hold all of the-grate bars in edgewise contact with eachotherand with the pallet frame and thereby cause the entire pallet toexpand together, the said means including tapered ribs and coenga 'nggrooves along the meetof the first series of bars to dislodge thecontents of the pallet.

ate construction for sintering adapted to be moved bodily out o theplane 11. In a sintering machine wherein is provided a series of alletsand means for moving said pallets in a train through a continuous pathand inverting the pallets 5 to discharge the load, a set of palletgrates for each pallet, each comprising a set of fixed bars and a set ofmovable g ate bars and means for limiting the motion of said movablebars to a direction substantially at right angles to the plane of thegrate to 1) thereby dislodge the contents of the pellets upon 1nversionthereof AUGUST L. LARSON.

